top 5 after colony gundam wing mobile suit

no 5.
gundam deathscythe

The Gundam Deathscythe was the "masterpiece" of Professor G. It was developed to be a master of infiltration, relying on shock and awe tactics to quickly and effectively accomplish its missions. To this end, one of its primary features was a pair of Hyper Jammer ECM suites mounted on its backpack. When in use, they prevented the Gundam from showing up on radar or visual sensors, rendering it invisible to most electronics. This allowed it to sneak into facilities and even right up to enemy mobile suits without being detected.
Once in combat, the Deathscythe's primary weapon was its namesake beam scythe. The power and overall reach of the scythe enabled it to destroy most single (and sometimes multiple) targets in one sweep, while its high thruster count let it move rapidly from target to target. The Deathscythe also typically carried a Buster Shield on its left arm, which doubled as launchable scissor katar. Rounding out its arsenal was a set of standard head-mounted vulcan guns and collar-mounted machine cannons.
As effective in combat as these features made it, perhaps the greatest weapon the Deathscythe bore was simply the fear it generated. The suddenness with which it arrive, its invisibility on sensors, and the speed and ferocity of its attacks were all designed with psychological warfare in mind. So too was its sinister appearance, incorporating elements such as a bat-like silhouette and hooded, grim reaper visage. All of these factors would make the Deathscythe a singularly fearsome and formidable machine - especially in the hands of the self-styled "God of Death", Duo Maxwell.

no 4. XXXG-01S2 Altron Gundam

Altron was built from the damaged frame of Shenlong, the Gundam scientists quietly used the OZ manufacturing facilities from the moon to upgrade the Gundam with new equipments and weaponry. Altron is still a melee-type fighter, but also given additional mid-range weaponry. Overall, Altron has twice the fire power and combat capabilities than its predecessor.
While Shenlong had only one Dragon Fang (a claw with a pair of built-in flame throwers mounted on an extendable arm), Altron has two of them, one on each extendable arms. The original beam glaive is replaced with a twin beam trident. A pair of beam cannons have been added to its back on a "Stinger Tail" . Altron was configured and adapted for space combat; its cockpit is now pressurized and a pair of stabilizer wings was added on its back for greater flight control. The only thing left unchanged was Shenlong's Shield. It was left attached for Altron for charging and throwing, however, it was renamed into the Altron Shield. Added with Chang Wufei's martial arts combat skills when piloting, Altron is one of the most formidable in melee combat.

 no.3  XXXG-01H Gundam Heavyarms

 Developed by Gundam Scientist Doktor S, the Heavyarms was developed in the L3 Colonies under the financial support of the Barton Foundation. The design concept of the Heavyarms was for it to have an extraordinary amount of guns: a heavy fire role. In the case that the Heavyarms uses up all its ammo, it features a retractable army knife on its right arm to engage enemies in close combat; while this made it the least close-combat capable Gundam of the 5 units, the lethality of its attack should still not be underestimated. When Heero Yuy borrowed the Heavyarms to engage in a duel with Zechs Merquise in his Tallgeese, the Heavyarms was refitted by Trowa to mount a fixed beam saber under the Beam Gatling. When its beam Gatling is not in use, it can be stored on the backpack.

no.2  XXXG-01SR2 Gundam Sandrock Kai

TV Version

An upgrade over the original Sandrock to make it capable of combat in space. Extra verniers were added to the shoulder armor, back skirt, backpack, and legs to increase mobility, and a beam machine gun was added in case the Sandrock Kai needed to engage in ranged combat. 

OVA Version

 

The OVA Version possibly has higher performance than the TV Version, as with the other four Gundams. Minor cosmetic changes were made, however, the weapons that are used remain the same. Any upgrades made to the weapons are unknown. The armor was also improved.
So far, it is unknown if the Sandrock Kai can still the Cross Crusher as neither versions have used it.

no 1.  XXXG-00W0 Wing Gundam Zero

 Wing Zero was designed by the five Gundam engineers fifteen years prior to the events of the Eve Wars. It is the ancestor of the five Operation Meteor Gundams (Wing, Deathscythe, Heavyarms, Sandrock, and Shenlong). Designed with "Perfect Victory" in mind, it boasts exceptional abilities and is one of the two suits which utilize the ZERO System (the other being the Gundam Epyon), but because of this dangerous mental interface, it was ultimately never constructed. The plans remained hidden away until Quatre Raberba Winner desperately built it to carry out his revenge following his father's death. Unlike the gundams constructed based on its design, the Wing Gundam Zero was built to be capable of both ground and space combat from the beginning. Like the Wing Gundam, it can transform into a high-speed flight mode dubbed "Neo-Bird Mode." Furthermore, its signature twin buster rifle has more than twice the output of the Wing Gundam's buster rifle, giving it enough power to destroy an entire space colony or resource satellite in a single shot. It features hidden thrusters in the shoulder armor, where the armor splits open to reveal the nozzles. The feet also house powerful thrusters in order to give the Neo-Bird Mode extreme speed.